Photographic elements containing a synthetic surface active material and inert particles



United States Patent PHOTOGRAPHIC ELEMENTS CONTAINING A SYN- THETIC SURFACE ACTIVE MATERIAL AND INERT PARTICLES Raymond Snellman and George D. Hill, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed May 5, 1965, Ser. No. 453,509

Int. Cl. G030 1/86 US. CI. 96-67 22 Claims ABSTRACT OF THE DISCLOSURE Photographic elements which contain layers containing a synthetic surface active material in which there is an acid function and a substituted amino group, such as the sodium salt of N-oleyl-N-methyl taurine, and inert particles, such as silica, barium sulfate, polymeric particles and the like, which have a particular particle .size range provide desired properties for very rapid access processing.

This invention relates to novel photographic elements. In one of its aspects, this invention relates to novel photographic elements suitable for rapid access photographic recording. In another of its aspects, this invention relates to photographic silver halide emulsion layers which give good photographic images when developed quickly at high temperatures.

In the photographic recording field a very short access time, i.e., the time interval between the exposure of a photosensitive recording material and the presentation of the resulting record for visual observation, is necessary or at least very desirable. Wind tunnel and flight testing are examples of procedures where rapid access is of considerable value. Both the desirability of rapid access processing and apparatus employed for this purpose are described in an article by J. H. Jacobs entitled Flash Processing: A Rapid Access Photographic Technique, Photo. Sci. and Eng., vol. 1, No. 4, March 1958, pp. 156-160, US. Patent 3,088,824 and British Patent 647,922.

Rapid access processing can be accomplished by moving a strip of photographic recording medium through a magazine at high speed past a spot of light which moves in accordance with the signal to be measured. As soon as the recording medium moves past the light spot, the photographic emulsion is wetted within a thin film of a high speed alkaline processing solution which is almost immediately dried as the recording medium passes over a hot platen. The dried, developed record emerges from the magazine within a very short time, for example, one second or less. Since only a thin film of developing solution is applied to the recording medium, it is necessary that the developing solution spread evenly over the surface of the recording medium to obtain uniform development. Also, it is necessary for the emulsion layer to pick up a suflicient amount of developer solution quickly in order to ensure complete development, although excess developer pick up must be avoided so that the emulsion layer will dry quickly. It is evident that a photographic element which can be employed in rapid access processing procedures and which can be evenly developed and dried quickly will substantially enhance the art.

Accordingly, it is an object of this invention to provide a novel photographic element.

Another object of this invention is to provide a photographic element that can be processed rapidly and evenly at high temperatures.

Still another object of this invention is to provide a photographic element comprising a flexible support and a 3,502,473 Patented Mar. 24, 1970 'ice hardened photographic silver halide layer that can be processed rapidly and evenly.

Still another object of this invention is to provide a photographic element comprising a hardened silver halide gelatin emulsion layer containing a unique combination of ingredients which element can be processed rapidly and evenly.

Still another object of this invention is to provide a photographic element comprising a flexible support, a hardened photographic silver halide gelatin emulsion layer, a surface active material and solid inert particles having a certain average particle size.

Other objects of this invention will become apparent from an examination of the specification and claims that follow.

In accordance with this invention, it has been found that rapid and even processing at high temperatures can be accomplished with a photographic element which comprises a flexible support, a hardened protographic silver halide emulsion layer containing a synthetic surface active material and inert particles having a certain particle size in at least one layer which is no farther from the support than the emulsion layer, all as described herein.

Surface active materials have been incorporated into photographic elements, particularly into photographic silver halide emulsion layers of such elements in the past. These surface active materials, sometimes called surfactants or spreading agents, are classified as anionic, cationic or nonionic, depending upon whether or not they ionize and if so, depending upon whether the anion or cation is surface active. It could not have been expected that only a particular class of surface active materials, as described herein, could be employed in the preparation of photographic elements which could be processed uniformly and rapidly at high temperatures. However, as shown in Example 3 that follows, other classes of surface active materials as exemplified by the naturally occurring surface active material saponin or a synthetic surface active material such as the sodium salt of an alkyl substituted aryloxy alkylene ether sulfonate, do not give the desired results when used in combination with the inert particles in the photographic elements described herein. Furthermore, as shown by Example 4 which follows, the inert particles present in the photographic elements must have a particular average particle size in order to achieve the desired results. I

The surface active materials employed in the practice of this invention are synthetic surface active materials which contain both an acid function and a substituted amino group. The nitrogen atom in the substituted amino group is bonded directly to all adjoining atoms by covalent bonds, i.e., there is a sharing of electrons rather than a transfer of electrons, as in an electrovalent bond. The acid function of the surface active agent can be present as the free acid or in the salt form, as for example, an alkali metal, ammonium or organic amine salt. The preferred class of synthetic surface active materials contain an acid function which is a carboxyl (COOH) or sulfo (SO H) group or salt thereof and only one substituted amino nitrogen atom bonded to a carbon atom beta to the acid function. Such synthetic surface active materials are ionic and include, for example, substituted amino alkyl sulfonic acids and salts having the formula:

where R is an aliphatic hydrocarbon radical, desirably containing 11 to 18 carbon atoms and R is an aliphatic hydrocarbon radical, preferably an alkyl radical of l to 4 carbon atoms or phenyl or cycloalkyl and M is a cation, preferably one contributing to water solubility of the surface active material. Suitable cations include hydrogen, an alkali metal, ammonium, an organic amine, or the like. Suitable R radicals include, for example, undecyl, dodecyl, pentadecyl, heptadecyl, while R is examplified by radicals such as methyl, ethyl, propyl, butyl, phenyl, cyclohexyl, and the like. Examples of M include hydrogen, sodium, potassium, lithium, ammonium or organic amine cations such as triethyl amine, tn'ethanol amine, morpholine, piperidine, and the like. Some compounds of this type which give good results in the practice of this invention are N-oleyl-N-methyl taurine, N-myristoyl-N- methyl taurine, N-stearoyl-N-methyl taurine, N-palmitoyl- N-methyl taurine, N-lauroyl-N-methyl taurine, N-myristoyl-N-butyl taurine, N-ricinoleyl-N-methyl taurine, and the like. These compounds are often employed in the form of their alkali metal salts, particularly sodium, although the free acid or other salt form can be used if desired. Synthetic surface active materials of this type are described in US. Patent 2,739,891, issued Mar. 27, 1956.

Good results are also obtained in practicing this invention with beta-alanine derivatives of the type disclosed in U.S. Patent 3,133,816, issued May 19, 1964. These spreading agents have the formulae:

RNHCH CH COOM and RN( CH CH COOM 2 Where R in each formula represents an aliphatic hydrocarbon group of 8 to 20 carbon atoms, as exemplified by octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl; M is a cation such as hydrogen or ammonium, an alkali metal such as sodium, potassium, lithium, or an organic amine cation such as diethanolamine, triethylamine, morpholine or piperidine, and the like. Suitable synthetic surface active materials of this type include sodium-N-dodecyl-fl-amino propionate, N-decyl-fl-aminopropionic acid, potassium-N- tetradecyl-fi-aminopropionate, sodium-N-hexadecyl-fl-aminopropionate, sodium-N-octadecyl B aminopropionate, monosodium salt of N-dodecyl-fl-aminodipropionate and disodium-N-octadecyl-fi-aminodipropionate.

Other synthetic surface active materials which can be used with advantage in this invention are those having the formula:

RCON[ (CH COOM] where x is an integer of 1 to 2, R is hydrocarbon radical, preferably aliphatic, of 11 to 17 carbon atoms and M is a cation. Suitable R groups include, for example, undecyl, dodecyl, pentadecyl, heptadecyl, and M is a cation, preferably one which contributes to water solubility. Suitable cations include hydrogen, an alkali metal such as sodium, potassium or lithium, ammonium, an organic amine cation such as diethanol amine, morpholine or piperidine. Examples of such compounds include N-lauroyl-N-carboxymethyl glycine, N-oleoyl-N-carboxymethyl glycine, N-dodecyloxybenzoyl-N-carboxymethyl glycine, N-(2,4- di-tertiary-amyl phenoxy acetyl)-N-carboxymethyl glycine, N-stearoyliminodiacetic acid, N-stearoyliminodipropionic acid, N-myristoyliminodiacetic acid, N-pahnitoylirninodiacetic acid and the like. As in the case of the taurine derivatives, these compounds are often used in the form of their alkali metal salt or other salt forms.

The synthetic surface active materials employed in the practice of this invention can be incorporated into one or more layers of the photographic element using any method suitable for this purpose. For example, the surface active materials can be added to aqueous dispersions of photographic silver halide in gelatin or other colloids, and coated. In general, the surface active materials are employed in the photographic silver halide layer or layers in concentrations in the range of about 3 to about 50', preferably about 5 to about 20 mg. per square foot of support. If desired, the surface active materials can also be incorporated into layers other than a photographic silver halide emulsion layer, for example, in an antiabrasion layer, backing layer or interlayer. When this is done, it is generally desirable to use about the same concentration of surface active material as is used in the photographic emulsion layer.

The inert particles employed in the practice of this invention are water insoluble, solid particles and have an average size within a particular range. Thus, the inert particles have a diameter in the range of about 7 to about 15 microns, preferably about 8 to about 12 microns. In addition, no more than about 5%, by weight, preferably less than about 3%, by weight, of the particles have a diameter in excess of 20 microns. The size of the inert, discrete particles employed in practicing this invention can be readily determined by conventional procedures employed in the prior art for this purpose.

The inert particles employed in the practice of this invention include any of the water insoluble particulate organic or inorganic compounds which can be used to provide the photographic element with the required surface characteristics. Examples of suitable inert particles include starch, barium sulfate, calcium carbonate, cellulose esters such as cellulose acetate propionate, cellulose ethers such as ethyl cellulose, synthetic resins such as polymeric esters of acrylic and methacrylic acid, as exemplified by poly methyl methocrylate, polyvinyl resins such as polyvinyl acetate and polyvinyl alcohol, polycarbonates, homo and copolymers of styrene, inorganic oxides such as zinc oxides, silica glass, titanium dioxide, magnesium oxide and aluminum oxide, as well as hardened gelatin grains, calcium sulfate, calcium carbonate, barium carbonate and the like.

The discrete particles can be incorporated into one or more layers on an emulsion side surface of a support in a photographic element. These particles are incorporated into at least one layer which is no farther from the support than the emulsion layer, i.e., they are incorporated in the photographic silver halide emulsion layer and/or a layer lying between said emulsion layer and the support. The inert particles can also be put into both the photographic silver halide emulsion layer and an adjacent layer. Where the inert particles are incorporated into a layer between the photographic silver halide emulsion layer and the support, smaller particles, e.g., particles having an average diameter in the range of about 2 to about 5 microns, can be employed in the emulsion layer to give an additional improvement in the uniformity of development.

The solid inert particles are incorporated into the. photographic element of this invention using any method which will achieve uniform dispersion of the particles in one or more layers of the element. For example, the inert particles are not light sensitive and can be dispersed directly in a photographic silver halide coating solution or they can be dispersed in an aqueous solution or dispersion of the silver halide binding agent, which solution is mixed with a photographic silver halide emulsion prior to coating the latter to form a light sensitive layer. In general, the solid inert particles are present in the photographic element in concentrations in the range of about 20 to about 150, preferably about 30 to about mg./ft. of support.

Various colloids can be used as vehicles or binding agents in the photographic elements of this invention. Among such agents are gelatin, or other colloidal materials such as colloidal albumin, cellulose derivatives, synthetic resins such as polyvinyl compounds, acrylamide polymers or the like. It is often advantageous to employ combinations of binding agents. Suitable combinations include mixtures of gelatin with aqueous dispersions of polymerized ethylenically unsaturated compounds. The binding agents, particularly gelatin, are usually coated at coverages in the range of about 250 to about 1000, preferably about 400 mg. to about 700 mg./ft. of support.

The silver halides employed in the preparation of the light sensitive coatings described herein include any of the photographic silver halides, as exemplified by silver bromide, silver iodide, silver chloride or mixed silver halides such as silver chlorobromide or silver bromoiodide. These photographic silver halides can be coated at silver coverages of about 30 to about 50, preferably 45 to about 90 mg./ft. of support.

The photographic silver halide and other layers of the photographic elements can be hardened, i.e., made less soluble and more resistant to warm aqueous solutions, using any of the hardeners suitable for this purpose. Compounds which are often used in the photographic field for this purpose are hardeners such as aldehyde hardeners, aziridine hardeners, hardeners which are derivatives of dioxane, oxypolysaccharides such as oxy-starch, or oxy plant gums and other types of hardeners for gelatin and hydrophilic colloids.

The photographic layers described herein can be superimposed upon a Wide variety of supports. Typical flexible supports include those generally employed for photographic elements such as cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film and related films or resinous materials as well as very thin glass film, paper, and the like. Supports such as paper which are partially acetylated or coated with baryta or an ot-olefin polymer, particularly a polymer of an w-olefin containing 2-10 carbon atoms as exemplified by polyethylene, polyproylene, ethylene butene copolymers and the like, can also be employed.

The photographic elements of this invention can contain certain addenda in one or more layers to aid in even more uniform development. For example, organic diols, particularly alkane diols, can be incorporated into one or more layers of the photographic element, particularly gelatin containing layers which are no farther from the support than the emulsion layer to achieve this more uniform development. It was quite surprising that such materials would improve development since these materials have been used in the past only as plasticizers to improve the flexibility of gelatin layers. Suitable diols which can be employed include the aliphatic and cycloaliphatic diols in which the carbon chain is straight, branched, or cyclic. The alkane diols employed preferably contain at least 4 carbon atoms and the hydroxyls are separated by at least 3 carbon atoms. Suitable alkane diols are exemplified by 1,5-butanediol, 1,6-hexanediol, 2- methyl-2,4-pentanediol and related compounds, as described in Milton US. Patent 2,960,404. Particularly effective are the cycloalkane diols such as 2,5-norbornane diol and 2,6-norbornane diol which can be prepared as described in Bruson US. Patent 2,385,788 or Caldwell US. Patent 2,968,646. These compounds are generally employed in the photographic elements of this invention in concentrations in the range of about 0.5 mg. or about 20 mg., preferably about 1.5 mg. to about mg./ft. of support. It has also been found that the photographic elements of this invention can be processed at a faster rate if the photographic silver halide layers contain silver halide emulsion sensitizers containing at least one onium salt group. Such sensitizers generally contain one or more onium salt groups which are quaternary ammonium, quaternary phosphonium and/ or ternary sulfonium salt groups. The polyonium salts contain an onium salt group selected from the group consisting of quaternary ammonium, quaternary phosphonium and ternary sulfonium salt groups, linked through the onium atom by at least one bivalent organic radical to the onium group of another onium salt group selected from the group consisting of quaternary ammonium, quaternary phosphonium and ternary sulfonium salt groups. Examples of suitable onium salts include sulfonium lauryl triethyl ammonium perchlorate, nonyl dimethyl sulfonium-p-toluene sulfonate, n-decyltriethyl-phosphonium-p-toluene sulfonate, ethylene bis oxymethyl triethyl phosphonium chloride, ethylene bis oxymethyl-u-picolynium perchlorate, tetramethylene. bis

oxymethyl trimethyl phosphonium bromide, and the like. Suitable quaternary ammonium, quaternary phosphonium and ternary sulfonium salts are described in Carroll et al. US. Patents 2,271,622, 2,271,623, 2,288,226 and Beavers et al. US. Patents 2,940,851, 2,940,855 and 2,944,898. These onium salt containing sensitizers are generally employed in the practice of this invention in concentrations in the range of about 0.1 mg. to about 3 mg, preferably about 0.25 to about 1 mg./ft. 2 of suppc In addition to the synthetic surface active agents already described, it is also very desirable to have certain other surface active agents present in one or more layers of the photographic element. These added materials are salts of maleopimaric acid and can be used in the photographic silver halide emulsion layer and/or in one or more layers over said layer as well as layers lying between the emulsion layer and the support. The maleopimarates are described in US. Patent 2,823,123 and are exemplified by the alkali metal salts of maleopimaric acid. Suitable alkali metals are sodium, potassium and the like. The maleopimarates are coated at concentrations in the range of about 1 to about 500 mg./ft. of support.

The photgraphic elements of this invention can also contain additional addenda, particularly those known to be beneficial in one or more layers of a photographic ele ment. For example, these elements can contain stabilizers or antifoggants such as organic azoles, metal salts such as cadmium, lead, mercury, gold, or other noble metal salts, spectral sensitizers such as the cyanines, merocyanines, complex(tn'nuclear)cyanines, complex(trinuclear)mer0cyanines, styryls, hemicyanines, speed increasing materials, gelatin hardeners, plasticizers and the like. The photographic silver halide emulsions can also be chemically sensitized with compounds of the sulfur group, noble metal salts such as gold or reduction sensitized with reducing agents or combinations of such materials.

The invention can be further illustrated by the following examples of preferred embodiments thereof although it will be understood that these examples are included merely for purposes of illustration and are not intended to limit the scope of the invention unless otherwise specifically indicated.

EXAMPLE 1 The photographic elements of this invention which contain a combination of a surface active material and inert solid particles, as described herein, can be processed uniformly and rapidly at high temperatures. To illustrate, a paper support is coated with agelatin layer (350 rng./ft. containing silica particles having an average diameter of 10 microns with no more than 5%, by weight, of the particles having an average diameter greater than 20 microns (65 mg./ft. and sodium salt of N-oleyl-N- methyl taurine (6.8 mg./ft. Over this layer is coated a silver bromoiodide gelatin emulsion layer (63 mg. silver and mg. gelatin/ft?) hardened with formaldehyde (8.5 mg./ft. and containing sodium salt of N-oleyl-N- methyl taurine (3.3 mg./ft.

A sample of the emulsion coated paper is exposed on an oscillograph and processed at 25 inches per second with a platen temperature of 250 C. using a rapid processing surface application drum processor of the type described in U.S. Patent 3,088,824, such as a Consolidated Electrodynamics Corporation Model 5-036 Datarite Magazine Processor. The coating exhibits good evenness in development and has a run out of over 40 feet.

Run out is the number of feet of paper which can be run through a processor of this type before the paper goes wet, i.e., too much developer is picked up for the hot platen to dry in the short time available.

When the above procedure is repeated with a photographic element in which the gelatin layer is omitted and the silica particles are present in the emulsion layer, a run out between 40 and 45 feet is achieved. The processed coating also shows good even development.

7 EXAMPLE 2 The procedures of Example 1 are repeated using coatings in which the sodium salt of N-oleyl-N-methyl taurine is replaced by the sodium salt of N-myristoyl-N-methyl taurine, N-myristoyl-N-butyl taurine, sodium-N-dodecyl B-amino propionate and sodium-N-myristoyl imino diacetate, respectively. In each run the coatings have good evenness of development and run out beween 40 and 45 feet.

EXAMPLE 3 When a natural surface active material such as saponin or a synthetic surface active material such as sodium-ptert-octyl phenoxy ethoxy ethyl sulfonate is employed in the practice of this invention, very poor results are obtained. To illustrate, the procedures of Example 1 are repeated using coatings in which the sodium salt of N-oleyl-N-methyl taurine is replaced by saponin (3.6 rug/ft?) and sodium p-tert-octyl phenoxy ethoxy ethyl sulfonate (3.3 m./ft. Upon processing, the coatings have poor to fair evenness of development and a run out of only 21 to 30 feet, Le, a decrease of at least 25% in comparison to Example 1.

EXAMPLE 4 Both organic and inorganic particles can be employed in the practice of this invention. To illustrate, a series of coatings is made using the procedures of Example 1 with coatings in which the silica is replaced by other inert particles. In each case the particles have an average diameter in the range of about 7 to about 15 microns with no more than by weight, of the particles having an average diameter in excess of 20 microns. The particles employed in the coatings are glass beads, barium sulfate, zinc oxide and poly methyl methacrylate beads, respectively. In each case, there is obtained the even development and good run out described in Example 1.

In contrast to the above, the desired results are not obtained if more than 5%, by weight, of the inert particles have an average diameter greater than 20 microns. Thus, a repeat of the above procedures using particles, by weight of which have an average diameter greater than microns, gives an excessive amount of developer pick-up and the coated papers do not dry in the short time available for processing. In addition, the processed papers show excessive print out, i.e., the background areas turn dark. Furthermore, when coatings contain inert particles having an average diameter of about 5 microns there is insufficient development and the D of the processed print is low.

EXAMPLE 5 The photographic silver halide emulsion sensitizers containing at least one onium salt group can be used in the photographic elements of this invention to improve processing characteristics. To illustrate, a series of coatings is made according to the procedures described in Example 1 except that N,N'-ethylene-di(oxymethyl pyridinium perchlorate) (0.54 -mg./ft. is added to the emulsion layer. When these coatings are processed as in Example 1, the rate of processing can be increased up to 10%, as shown by an increase in the number of ft./sec. of paper put through the hot drum processor.

Similar results are obtained when N,N'-ethylene-di- (oxymethyl pyridinium perchlorate) is replaced with other onium salts such as 1,10-decamethylene-bis-triethyl ammonium perchlorate, bis(lauryl methyl sulfonium ptoluene sulfonate)-1,4-butane, n-nonyl-dimethyl sulfonium-p-toluene sulfonate or decyl pyridinum perchlorate. When onium salts containing only one onium group are used in practicing this invention they preferably contain a chain of at least 7 atoms attached to the onium group.

8 EXAMPLE 6 As pointed out previously, certain diols and salts of maleopimaric acid can be incorporated into one or more layers of a photographic element of this invention to further improve processing characteristics. To illustrate, a series of coatings is prepared as in Example 5 using the procedure in which a gelatin layer is coated over the paper support. Sodium maleopirnarate is incorporated into both the gelatin layer (2.2 mg./ft. and silver bromoiodide emulsion layer (1.1 mg/ft?) and norbornane diol is incorporated into the silver bromoiodide emulsion layer (2.7 mg./ft. Upon processing as in Example 1, further improvements in evenness of development and run out performance are achieved.

Although the invention has been described in considerable detail with reference to preferred embodiments thereof it will be understood that variations and modifications can be effected without departing from the spirit and scope of the invention as described herein and as defined in the appended claims.

We claim:

1. A photographic element comprising a flexible support, a hardened photographic silver halide emulsion layer containing a synthetic surface active material in which there is a carboxyl or sulfo group or salt thereof and a substituted amino group and, incorporated in at least one layer which is no farther from said support than said photographic silver halide layer, inert particles having an average diameter in the range of about 7 to about 15 microns with no more than about 5%, by weight, of said particles, having a diameter in excess of about 20 microns.

2. The photographic element of claim 1 in which the flexible support is a paper support.

3. A photographic element comprising a flexible support, a hardened gelatin photographic silver halide emulsion layer containing a cationic synthetic surface active material in which there is a carboxyl or sulfo group or salt thereof and a substituted amino group and, incorporated in at least one layer which is no farther from said support than said photographic silver halide layer, inert particles having an average diameter in the range of about 7 to about 15 microns with no more than about 5%, by weight, of said particles having a diameter in excess of about 20 microns.

4. The photographic element of claim 3 in which the hardened photographic silver halide emulsion is a hardened silver bromoiodide layer.

5. The photographic element of claim 3 in which the flexible support is a paper support.

6. A photographic element comprising a flexible support, a hardened photographic silver halide emulsion layer containing a synthetic surface active material in which there is a carboxyl or sulfo group or salt thereof and a substituted amino group and inert particles having an average diameter in the range of about 7 to about 15 microns with no more than about 5%, by weight, of said particles having a diameter in excess of about 20 microns.

7. The photographic elemnet of claim 6 in which the flexible support is a paper support.

8. A photographic element comprising a flexible support, a hardened photographic silver halide emulsion layer containing a synthetic surface active material in which there is a carboxyl or sulfo group or salt thereof and a substituted amino group and, incorporated in at least one layer lying between said support and said photographic silver halide layer, inert particles having an average diameter in the range of about 7 to about 15 microns with no more than about 5%, by weight, of said particles having a diameter in excess of about 20 microns.

9. The photographic element of claim 1 in which the surface active material has the formula:

where R is an aliphatic hydrocarbon radical containing 11 to 18 carbon atoms, R is a member selected from the group consisting of aliphatic hydrocarbon radicals containing 1-4 carbon atoms, phenyl and cycloalkyl and M is a cation.

10. The photographic element of claim 9 in which the flexible support is a paper support.

11. The photographic element of claim 1 in which the surface active material has a formula selected from the group consisting of:

(I) RNHCHgCHzCOOM and (II) RN(CH CH COOM) where R, in each of the above formulas, is an aliphatic hydrocarbon group of 8 to 20 carbon atoms and M is a cation.

12. The photographic element of claim 1 in which the surface active material has the formula:

where R is a hydrocarbon radical of 11 to 17 carbon atoms, x is an integer of 1 to 2 and M is a cation.

13. A photographic element comprising a flexible support, a hardened photographic silver halide emulsion layer containing a surface active material having the formula:

where R is an aliphatic hydrocarbon radical containing 11 to 18 carbon atoms, R is a member selected from the group consisting of aliphatic hydrocarbon radicals containing 1-4 carbon atoms, phenyl and cycloalkyl and M is a cation and, incorporated in at least one layer which is no farther from said support than said photographic silver halide layer, inert particles of an inorganic oxide having an average diameter in the range of about 7 to about 15 microns with no more than about by weight, of said particles having a diameter in excess of about 20 microns.

14. The photographic element of claim 13 in which the inorganic oxide is silica.

15. The photographic element of claim 13 in which the flexible support is a paper support and the inorganic oxide is silica.

16. A photographic element comprising a flexible support, a hardened photographic silver halide emulsion layer containing (1) a synthetic surface active material having the formula:

where R is an alihatic hydrocarbon radical containing 11 to 18 carbon atoms, R is a member selected from the group consisting of aliphatic hydrocarbon radicals containing 1-4 carbon atoms, phenyl and cycloalkyl and M is a cation, and (2) a photographic silver halide emulsion sensitizer containing at least one onium salt group and, incorporated in at least one layer which is no farther from said support than said photographic silver halide layer, silica particles having an average diameter in the range of about 7 to about 15 microns with no more than about 5%, by weight, of said particles having a diameter in excess of about 20 microns.

17. A photographic element comprising a flexible support, a hardened photographic silver halide emulsion layer containing (1) a synthetic surface active material in which there is a carboxyl or sulfo group or salt thereof and a substituted amino group and (2) a photographic silver halide emulsion sensitizer containing at least one onium salt group and, incorporated in at least one layer which is no farther from said support than said photographic silver halide layer, inert particles having an average diameter in the range of about 7 to about 15 microns with no more than about 5%, by weight, of said particles having a diameter in excess of about 20 microns.

18. The photographic element of claim 17 in which the onium salt group of the photographic silver halide emulsion sensitizer is a quaternary ammonium salt group.

19. The photographic element of claim 1 in which there is incorporated in at least one layer which is no farther from the support than the photographic silver halide layer, a member selected from the group consisting of aliphatic and cycloaliphatic diols.

20. A photographic element comprising a flexible support, a hardened photographic silver halide emulsion layer containing (1) a synthetic surface active material in which there is a carboxyl or sulfo group or salt thereof and a substituted amino group and (2) an alkali metal salt of maleopimaric acid and, incorporated in at least one layer which is no farther from said support than said photographic silver halide layer, inert particles having an average diameter in the range of about 7 to about 15 microns with no more than about 5 by Weight, of said particles having a diameter in excess of about 20 microns.

21. A photographic element comprising a paper support having a gelatino coating containing silica particles having an average diameter of about 10 microns with no more than 5%, by weight, of the particles having an average diameter greater than 20 microns and a sodium 'salt of N-oleyl-N-methyl taurine and, on said gelatino coating, a prehardened photographic silver halide emulsion layer containing N-oleyl-N-methyl taurine.

22. A photographic element as in claim 1 wherein the surface active material is selected from the group consisting of the sodium salts of N-oleyl-N-methyl taurine, N- myristoyl-N-butyl taurine, N-dodecyl-p-amino propionate and N-myristoyl imino diacetate.

References Cited UNITED STATES PATENTS OTHER REFERENCES Photo Methods for Industry, February 1959, pp. 32-35, 72-73.

Ansco Abstract, 1,451 Ila.

NORMAN G. TORCHIN, Primary Examiner MARY F. KELLEY, Asssitant Examiner U.S. Cl. X.R. 9685 

